Bryant 542F - User Manual

DESCRIPTION
Model 542F is a high-efficiency, single-package heat pump that
has an energy efficiency ratio (EER) of 8.5 and a coefficient of
performance (COP) of 3.0 at 47 F outdoor temperature rating
point.
The 542F has supply- and return-air openings on the bottom of
the unit and is designed primarily for rooftop installation on a
factory-supplied 14- or 24-in. high roof curb. The air ducts con-
nect to the curb only; therefore, the curb and ductwork may be
installed before the unit arrives at the jobsite.
A 24-in. high factory-supplied adapter for horizontal supply/
return duct connections to an over-and-under duct configuration
is also available for grade level or rooftop installation.
‘‘Variable circuited’’ indoor and outdoor coils allow both coils to
operate with parallel circuits when they are performing as
evaporators, and with a series of circuits when they are perform-
ing as condensers.
STANDARD FEATURES
FACTORY-ASSEMBLED PACKAGE is a compact, fully self-
contained heating/cooling unit that is prewired, prepiped, and
precharged for minimum installation time and expense.
TWO RUGGED, SERVICEABLE, SEMI-HERMETIC COM-
PRESSORS provide two stages of heating and cooling. These
compressors are electrically and mechanically independent.
COMPRESSOR ISOLATION MOUNTING minimizes vibration
(noise) transmission to building.
TWO SUCTION-TUBE ACCUMULATORS protect compres-
sors against liquid slugging — permitting operation over wide
range of temperatures.
CRANKCASE HEATERS AND FILTER DRIERS are standard.
HIGH- AND LOW-PRESSURE SAFETY DEVICES are included
to prevent major component breakdown when abnormal refrig-
erant operating conditions occur.
INTERNAL AND EXTERNAL PROTECTION is provided
against compressor overload and overheat conditions.
HIGH-STATIC, BELT-DRIVEN BLOWER with an adjustable
motor pulley permits variable airflow rates. An optional motor
pulley adjusts the airflow range to meet most applications.
WEATHERIZED CABINET of heavy-duty phosphated and zinc-
coated steel is standard. Baked-on finish is corrosion and fade
resistant.
VERTICAL CONDENSER AIR DISCHARGE prevents recircu-
lation of hot condenser air and reduces the operating sound
level.
MANUAL OUTDOOR-AIR DAMPER (standard equipment on
units without optional economizer) provides up to 25% outdoor
air for ventilation.
SUPPLEMENTAL ELECTRIC HEATERS are available as ac-
cessory equipment for operation on 208, 230, and 460 v, and
are modular in design for easy installation.
SINGLE-POINT POWER CONNECTION is provided on units
with field-installed electric heaters. Only one power supply with
one disconnect switch is required.
PROTECTION AS REQUIRED BY NEC (National Electrical
Code) for fan motors is factory supplied.
TWO-IN. FILTERS are standard.
RIGGING HOLES are provided in unit base rails for a 4-point lift
to facilitate lifting and moving operations.
THERMALLY AND ACOUSTICALLY INSULATED air-handling
section provides quieter and more efficient operation.
FACTORY-INSTALLED OPTIONS
DESCRIPTION AND USAGE
Economizer — The economizer will allow a fixed percentage
(between 0 and 100%) outdoor ventilation air into the unit any
time the indoor fan is running. Adry-bulb changeover thermostat
allows up to 100% outdoor air whenever the temperature of the
outdoor air alone will adequately provide cooling. If the econo-
mizer alone cannot provide enough cooling, then simultaneous
economizer and compressor operation will provide the most
economical operation.
SUGGESTED USE:
• To allow a fixed percentage of outdoor air any time the indoor
fan is on, or operates in economizer mode if outdoor air can
provide cooling, but closes when the indoor fan is off to pre-
vent cold backdrafts and wasted energy.
• To reduce energy usage. Use whenever the number of hours
of operation at below 55 F is significant.
• The damper may be used on either vertical or horizontal
applications.
Alternate Indoor-Fan Drive — Alternate drive allows operation
of the indoor fan at conditions outside the range of the standard
factory motor and drive combination.
SUGGESTED USE:
• When higher static/airflow is required to meet job conditions.
MODEL 542F
Bryant
Air Conditioning
COMMERCIAL ROOFTOP
PACKAGED HEAT PUMP
Model 542F
Size 180
15 Tons
Form No. PDS 542F.180.2B

Summary

Unit Description and Standard Features

Model 542 F Overview

Description of the Model 542F as a high-efficiency, single-package heat pump.

Standard Features

Key features of the base unit including compressors, fans, and protection systems.

Factory-Installed Options

Field-Installed Accessories

Unit Specifications and Performance Data

ARI Capacity Ratings

Gross cooling and integrated heating capacities at various conditions.

Detailed Unit Specifications

Unit Operating Weight and Components

Fan and Motor Specifications

Pressure Switches and Filters

Selection Procedure and Performance Calculations

Determine Cooling and Heating Requirements

Procedure to determine unit cooling and heating capacity needs.

Select Unit Based on Cooling Capacity

Guidance on selecting the unit based on required cooling capacity.

Select Electric Heat

Procedure for selecting appropriate electric heat capacity.

Determine Fan Speed and Power Requirements

Determine Net Capacities

Calculation of net cooling and heating capacities, accounting for fan heat.

Capacity and Performance Tables

Gross Cooling Capacities

Table of gross cooling capacities (Btuh) and compressor kW.

Integrated Heating Capacities

Table of integrated heating capacities (Btuh) and total power input (kW).

Air Delivery and Static Pressure

Air Delivery Performance

Table showing fan RPM and brake horsepower (BHP) at various airflows and static pressures.

Electrical and Pressure Data

Electrical Data

Electrical data including RLA, LRA, FLA, MCA, MOCP for unit components.

Operating Sequences

Base Unit Operating Sequences

Sequences for cooling, heating, and defrost cycles without an economizer.

Economizer Operating Sequences

Sequences for cooling and heating with an economizer.

Accessory Operating Sequences

Wiring and Installation Diagrams

Typical Field Wiring Diagram

Schematic showing typical field wiring connections for unit control.

Engineers Specification Guide

General Unit Requirements

General requirements for a self-contained electric heat pump rooftop unit.

Cooling and Heating Capacity Specifications

Specifications for cooling capacity (EER) and heating capacity (COP).

Cabinet and Compressor Specifications

Outdoor and Indoor Section Specifications

Control Circuit and Approvals

Bryant 542F Specifications

General

Type	Heat Pump
Refrigerant	R-410A
Phase	1
HSPF Rating	Up to 9.0
Voltage	208/230
Cooling Capacity (BTU/h)	24000-60000